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Advisory Committee Chair

David C Knight

Advisory Committee Members

Sylvie Mrug

Rajesh K Kana

Edwin W Cook

Kristina M Visscher

Document Type

Dissertation

Date of Award

2021

Degree Name by School

Doctor of Philosophy (PhD) College of Arts and Sciences

Abstract

Violence exposure during childhood and adolescence is associated with susceptibility to internalizing disorders such as depression and anxiety. The relationship between childhood violence exposure and internalizing disorders may be explained by changes in brain function. For example, childhood maltreatment, including violence exposure, is associated with changes in brain regions that are important for emotion regulation. Reciprocal connections among these brain regions are important for healthy responses to stress. Thus, examining how childhood violence exposure varies with acute stress-induced changes in functional brain connectivity and psychophysiological stress responses may elucidate how childhood violence exposure may contribute to susceptibility to internalizing disorders. This project employed functional magnetic resonance imaging to examine whether childhood violence exposure varies with stress-induced resting state functional connectivity (rsFC) and the psychophysiological response (e.g., heart rate, skin conductance level (SCL)) to stress. Specifically, the project examined whether violence exposure varied with rsFC, stress-induced changes in rsFC, heart rate, and SCL, and whether affective style modulates rsFC. We found that violence exposure does not vary with resting heart rate and SCL. Additionally, we found that the rsFC within the prefrontal cortex (PFC) varies negatively with childhood violence exposure. Further, stress-induced changes in rsFC varied with violence exposure and affective style. For instance, among participants with higher positive affective style, violence exposure did not vary with post-stress amygdala-inferior parietal lobule (IPL) rsFC. This finding suggests that high positive affect can mitigate the relationship between violence and the brain. Additionally, we observed that heart rate and SCL varied both negatively and positively with rsFC among brain regions such as the amygdala, hippocampus, PFC, insula, IPL, parahippocampal gyrus, and cingulate, suggesting that interconnections among these regions underlie peripheral emotional responses. Further, amygdala-IPL rsFC varied negatively with heart rate post-stress among those with high, but not low violence exposure. These findings suggest that connectivity among these brain regions modulates the stress responses in those exposed to high levels of violence. Overall, findings suggest that childhood violence exposure varies with the rsFC of brain regions that are important for the expression and regulation of emotion, and modulate peripheral emotional responses.

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